When athens became too powerful, which city-state stood up to them?

Salutations!

When Athens became too powerful, which city-state stood up to them?

When Athens became too powerful, Sparta was the city state that stood up to them. Athens and Sparta fought as allies for a very longtime. While Sparta was fighting the decades war, Athens went bankrupt, as thus, as friendly allies, Sparta provided a helping hand.

Hope I helped :D